move package publishing template back to project-config
move package publishing template back to project-config

The publish-to-pypi-python3 template should never have been set here
in the repo because we need to manage it in a place that does not have
different branches.

Change-Id: I308dd851667f21f01030118596841279280eb883
Depends-On: https://review.openstack.org/580507
Signed-off-by: Doug Hellmann <0798ebecfb7bc4dfb9d0445c2fa030eb64e1fa1c@doughellmann.com>

openstack/reno